First of all you Have to use prepare and execute with select.
Only with select though, it makes the execution of the whole thing faster.
With everything else use 'do'

and second to do what you want, do it like this (the right way....)

my $dbh = DBI->connect('DBI:mysql:foo','foo','foo') 
          or die "Connect Error: $DBI::errstr";

my $count_sth = $dbh->prepare("SELECT COUNT(*) FROM company_info;") 
                or die "Prepare Count Error: $DBI::errstr\n";

$count_sth->execute() 
           or die "Execute Count Error: $DBI::errstr\n";

print $count_sth->fetchrow;

$count_sth->finish;
$dbh->disconnect;
[download]

Isn't it simple ?